Spatiotemporal variations of surface deformation, shallow creep rate and slip partitioning between the San Andreas and southern Calaveras faults constrained by InSAR

Yuexin Li, & Roland Bürgmann

Published August 16, 2021, SCEC Contribution #11617, 2021 SCEC Annual Meeting Poster #101

The Calaveras Fault (CF) is one of the main active faults in the San Andreas Fault (SAF) system in the San Francisco Bay Area, accommodating ~15 mm/yr of long-term slip along its central and southern sections. At the CF-SAF junction, the southern Calaveras Fault branches from the SAF at San Benito, extending sub-parallel to the SAF for ~60 km with only 2-6 km separation until south of Hollister. Both the CF and SAF have been reported to have spatially-variable aseismic creep. In this study, we perform a timeseries analysis using 5 years of Sentinel-1 data (2015-2020) over the Bay Area, specifically targeting the CF-SAF junction. The InSAR LOS and continuous GPS velocities agree within 3 mm/yr in the study area. We assess the surface creep rate distributions along the two fault strands in the CF-SAF junction and their temporal signature. The detailed mapping of surface deformation around the CF-SAF junction will help better understand the potential interaction, slip partitioning and the role of the southern Calaveras Fault in the SAF system.

Citation
Li, Y., & Bürgmann, R. (2021, 08). Spatiotemporal variations of surface deformation, shallow creep rate and slip partitioning between the San Andreas and southern Calaveras faults constrained by InSAR. Poster Presentation at 2021 SCEC Annual Meeting.

Related Projects & Working Groups
Tectonic Geodesy